The field of the invention generally pertains to metal polishing and finishing. The present invention relates more particularly to a wheel finishing apparatus and method utilizing a carousel configuration to orbitally drive multiple wheels through abrasive polishing media, wherein the front face of each wheel is partially submerged in the abrasive polishing media and angled to be impinged at an impingement angle.
The popularity of stylized automobile wheels has been largely attributable to their aesthetic enhancement of automobiles, with chrome wheels in particular providing a more stylish, sporty, and expensive look. In order to provide such an aesthetically pleasing appearance the front face of a wheel must be made as smooth as possible before it is coated or plated with a layer of chrome. If the front face is not smooth, the chrome layer applied thereto acts to enhance and visually magnify any grooves or imperfections remaining in the wheel surface, thereby significantly detracting from the overall appearance of the wheel. Thus, there is a need for a device which may quickly and efficiently remove substantially all the grooves and roughness on the front face of a wheel to provide a front face with the desired degree of smoothness.
One prior method of finishing wheels has been to manually finish wheels by hand. A workman would manually rub an abrasive material against the front face of a wheel, e.g. by means of a hand-held polishing/buffing wheel, which would eventually serve to polish the front face of the wheel. This procedure has proved to be quite tedious, time-consuming, and labor and cost intensive, and thus very inefficient.
Another prior method of finishing wheels is shown in U.S. Pat. No. 5,857,901, showing an automobile wheel finishing apparatus having a vertical spindle mounted on a frame and positioned directly above a media tank. The lower end of the spindle is adapted to vertically mount a single wheel thereon. The single mounted wheel is rotated by the spindle as the media tank is raised to engage the front face of the automobile wheel with the media. The configuration of this apparatus, however, is not free from shortcomings. The particular vertical mounting of the wheel on the spindle and subsequent rotation thereof produces a centrifuge effect propelling abrasive polishing media in a radially outward direction. While suitably finishing the radial fringes of a wheel, this process has proved to be inadequate for finishing the inner surface areas of the front face. Moreover, the single wheel mounting configuration by means of a single spindle can be inefficient for finishing large numbers of wheels in a high volume manner.
In U.S. Pat. No. 4,615,145, a polishing apparatus not specifically geared for wheel polishing is shown having a planetary gear box which simultaneously produces three rotational motions on three separate and distinct axes. As shown in FIG. 1, this arrangement produces an orbiting motion about an orbit path F while simultaneously producing a rotational motion in the direction of r, and although not shown in FIG. 1, a third rotational motion is provided about axle b shown in FIG. 1. Because this particular configuration is designed to polish all surfaces of a work piece, it is largely inadequate and unsuitable for wheel polishing/finishing applications where it is necessary to finish only the front faces thereof for subsequent plating or coating. Furthermore, because wheels have a relatively broad front face, subjecting them to the particular multi-axial rotation disclosed in the ""145 patent while completely submerged in abrasive polishing media commonly used in wheel finishing applications, may strain the ""145 apparatus which is primarily intended for smaller items such as spoons, ladles, pipes, etc.
Therefore, there is a particular need to provide a wheel finishing apparatus that overcomes the limitations of the prior art with respect to both quality of the finished product, as well as the high-volume efficiency and cost-effectiveness by which wheel finishing operations are performed. The advantages of an improved multi-wheel finishing apparatus is readily and most notably apparent in the potentially substantial cost-savings in manual labor costs in this traditionally labor-intensive industry. Average manual finishing costs per wheel have been known to be as high as sixteen dollars per wheel, which has typically translated to higher prices for consumers and lower profits for manufacturers.
Thus, it is an object of the present invention to provide a simple, improved, and cost-effective wheel finishing apparatus and method configured to more completely polish the front face of the wheel in a high-output, efficient, and cost-effective manner.
It is a further and more particular object of the present invention to provide a wheel finishing apparatus and method arranged in a carousel configuration for perimetrically mounting multiple wheels thereon to concurrently impinge and finish the front faces of the multiple wheels in an abrasive polishing media.
It is a still further object of the present invention to provide a wheel finishing apparatus and method designed to cyclically submerge portions of the front faces of wheels in abrasive polishing media whereby improved operational performance may be realized due to overall decrease in drag, higher impingement speeds and abrasive impact forces, and shorter operation cycles.
It is a still further object of the present invention to provide a wheel finishing apparatus and method which automatically rotates mounted wheels such that all areas of the front face of the wheel are finished evenly without producing variations in finish quality.
The present invention is for a wheel finishing apparatus for abrasively finishing wheels having front faces. In a preferred embodiment, the wheel finishing apparatus has a frame and a carousel hub rotatably connected to the frame for rotating about a central axis of rotation. The carousel hub is preferably connected to the frame by means of a spindle which suspends the carousel hub from the frame. At least one carousel arm is fixedly connected to the carousel hub, each extending to a wheel mounting end remotely spaced from the central axis. Preferably, a plurality of carousel arms are provided by which multiple wheels may be mounted thereon. The carousel hub and arms are rotated together by means for rotating the carousel hub about the central axis of rotation in a known rotational direction. In this manner, the carousel hub and arms are rotated such that the wheel mounting end traverses an orbital path around the central axis of rotation. Rotation of the carousel hub and arms is preferably accomplished by a carousel motor connected to the spindle. The wheel finishing apparatus also has means for rotatably mounting a wheel to each wheel mounting end with the front face of each mounted wheel facing the known rotational direction and each mounted wheel having a wheel rotational axis oriented normal to the front face. The front face forms an impingement angle with the orbital path, which is preferably less than 90 degrees to produce a rotational moment exerted on a submerged portion of the mounted wheel during the finishing operation. Preferably, and in a second preferred embodiment, means for rotating the mounted wheel is provided by which the wheel is rotated about the wheel axis of rotation regardless of the impingement angle. Furthermore a tank is provided having an open end for storing abrasive polishing media. And means for partially submerging the mounted wheel in the abrasive polishing media is provided, which preferably includes hydraulic means for moving the tank and the wheel mounting ends relative to each other between engaged and disengaged positions. In the disengaged position, the wheels mounted on the wheel mounting ends are not submerged in the abrasive polishing media such that an operator may load and unload wheels from the wheel finishing apparatus. And in the engaged position, the mounted wheels are extended into the open end of the tank and are partially submerged in the abrasive polishing media such that the submerged portion of the front face of the mounted wheel is abrasively impinged by the abrasive polishing media at the impingement angle.
The present invention is also for a wheel finishing system for abrasively finishing wheels having front faces. The wheel finishing system comprises a wheel mounting structure having means for rotatably mounting at least one wheel thereon, with the at least one mounted wheel having a wheel axis of rotation normal to the front face. Additionally, the system also comprises a tank having an open end, for storing abrasive polishing media. Means for partially submerging the at least one mounted wheel in the abrasive polishing media is also provided so that a submerged portion of the front face is in contact with the abrasive polishing media. And finally, means for relatively moving the at least one partially submerged wheel through the abrasive polishing media in a known direction of relative motion is provided with the at least one partially submerged wheel angled to impinge the submerged portion of the front face at an impingement angle less than ninety degrees. The impingement angle is defined between the known direction of relative motion and the front face of the at least one partially submerged wheel. In this manner, when the at least one mounted wheel is partially submerged in the abrasive polishing media and relatively moved therethrough in the known direction of relative motion, the abrasive polishing media exerts a rotational moment against the submerged portion of the front face to rotate the partially submerged at least one wheel about its wheel axis of rotation and impinge all areas of the front face in a cyclical manner.
And finally, the present invention is also for a method of abrasively finishing wheels having front faces. The method provides for rotatably mounting at least one wheel onto a wheel mounting structure, such as the carousel hub and arms combination described above. The at least one mounted wheel is partially submerged in the abrasive polishing media such that a submerged portion of the front face is in contact with the abrasive polishing media. Then, the partially submerged wheels are relatively moved in a known direction of relative motion through the abrasive polishing media at the impingement angle formed between the front face of the partially submerged wheel and a known direction of relative motion. This causes the abrasive polishing media to impinge the submerged portion of the front face at the impingement angle. Where the impingement angle is less than ninety degrees, the abrasive polishing media causes rotation of the wheel along the wheel axis of rotation to evenly finish all areas of the front face.